Conditional mapping

[nyngwang]

I want to customize the mapping for <C-o> as below. In short, I want to combine both cmp.mapping.complete() and cmp.mapping.close() into one single mapping. Currently, this doesn't work:

mapping = cmp.mapping.preset.insert {
  -- <option-shift-P/N>
  ['<C-S-p>'] = cmp.mapping.scroll_docs(-4),
  ['<C-S-n>'] = cmp.mapping.scroll_docs(4),
  ['<C-o>'] = function () -- <------------------------here
    if vim.fn.pumvisible() == 1 then
      cmp.mapping.close()
    else
      cmp.mapping.complete()
    end
  end,
  ['<C-y>'] = cmp.mapping(
    cmp.mapping.confirm {
      behaviour = cmp.ConfirmBehavior.Insert,
      select = true
    }, { 'i', 'c' }
  ),

[nyngwang]

I'm noob, this can be done for sure:

          ['<C-o>'] = cmp.mapping {
            -- toggle completion menu.
            i = function ()
              if cmp.visible()
                then cmp.close()
                else cmp.complete() end
            end,
          },

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